The transport sector contributes to climate change, and it has been the target of public interventions to improve quality of life and reduce CO2 emissions. The Medellin metropolitan area (Colombia) has developed a mass transportation system called Metro de Medellin that integrates train lines, a tram line, BRTs, gondola lift systems, a bicycle-sharing system and hybrid buses to reduce traffic and CO2 emissions. Despite these efforts, pollution is peaking, and the situation requires new plans. The aim of this paper is to quantify the emissions that will be avoided by the implementation of Medellin's Master Plan, the promotion of telecommuting, and the development of a transport energy model for Medellin between 2010 and 2040. The results indicate that combining the promotion of mass transportation and telecommuting could represent 5.65 MTons of CO2 equivalent avoided by 2040 (9.4% reduction) and estimated total energy savings of 86,575.55 TJ. Therefore, it is necessary to implement complementary policies in order to achieve the commitment assumed by Colombia at the COP 21. The analytical framework used here could be applied to other regions in order to evaluate environmental and energy mitigation strategies, especially in the developing world where similar policies may be in place.